(1) Field of the Invention
The invention relates to an upper cover plate for an air-tight chamber and a tool for removing the upper cover plate, and more particularly to a plate structure and an accompanying tool which can make easier the breaking of the air-tight state of the chamber.
(2) Description of the Prior Art
Air-tight chambers are widely used in precision manufacturing. For example, in an electronic or a semiconductor industry, various types of air-tight chambers have been seen in a wafer-manufacturing process or the like. Conventionally, a middle-size or a large-size air-tight chamber is usually equipped with an automatic or a labor-saving mechanism for controlling opening/closing of a heavier air-tight door structure. However, due to a consideration of cost, a small-size air-tight chamber usually applies only a simple-structured cover plate for sealing the chamber. The opening, of the cover plate, i.e. the breaking of the air-tight or vacuum state of the chamber, is generally performed by utilizing a hand tool upon the cover plate.
Referring now to FIG. 1, a schematic side view of a typical air-tight chamber, say an Applied Eudura5500 PVD chamber, is shown. In this structure, the air-tight chamber includes a chamber body 1 and an upper cover plate 2. A top surface 13 of the chamber body 1 includes a annual groove 11 for accommodating an oil seal 12. A bottom surface 22 of the upper cover plate 2 is used to air-tightly mount upon the top surface 13 of the chamber body 1. By providing a plurality of screws (not shown in the figure), the upper cover plate 2 can be fastened onto the chamber body 1. At the same time, the oil seal 12 in the annual groove 11 can then be depressed and deformed in between to form an air-tight state of the chamber.
While beginning to disassemble the upper cover plate 2 from the chamber body 1, the screws in between need to be loosen firstly. At this time, due to the sealing effect provided by the oil seal 12, the upper cover plate 2 and the chamber body 1 are actually still integrated as an air-tight chamber. By applying substantial force upon a plurality of T-shaped tools 3 (2 shown in FIG. 1) engaged with the upper cover plate 2, the upper cover plate 2 then can be removed off the chamber body 1. During the removing of the upper cover plate 2, the air-tight state of the chamber is broken as soon as the oil seal 12 miss-contacts any of the upper cover plate 2 or the chamber body 1.
Referring now to FIG. 2, a conventional T-shaped tool 3 is shown perspective. The tool 3 includes a hand bar 31 for manual forcing operation, a stem bar 32 perpendicular to the hand bar 31, and an external thread part 33 formed at a free end of the stem bar 32. Please now refer back to FIG. 1. While applying the tool 3, each tool 3 is engaged directly with a respective blind thread hole 21 on the upper cover plate 2. Then, apply a lift to each tool 3 for separating the upper cover plate 2 from the chamber body 1; thus, the air-tight state of the chamber can be broken.
In the aforesaid chamber structure, it is obvious that the thread holes for fastening the upper cover plate 2 to the chamber body 1 and the blind thread holes 21 for engaging with the T-shaped tool 3 are all located outsides to the annual groove 11. On the other hand, the air-tight interior of the chamber is formed insides to the annual groove 11. Upon such an arrangement, the air-tight state of the chamber can be established by depressing the oil seal 12 located in the annual groove 11.
Apparently, in the application of the upper cover plate 2 and the T-shaped tool 3, a substantial lifting force is required directly to break the air-tight state of the chamber. Thus, a so-called hard-pulling mechanism is formed. Nevertheless, in practice, only limited room around the chamber is available for manual lifting operation of the T-shaped tool 3. Actually, in the example of the Applied Eudura 5500 PVD chamber, the disassembly of the chamber upon breaking the air-tight state is usually so difficult that substantial labor and time are required while carrying out a periodical or an urgent maintenance.
Accordingly, it is a primary object of the present invention to provide an upper cover plate for an air-tight chamber and a tool for removing the upper cover plate from the chamber, in which a top surface of a chamber body of the air-tight chamber can be utilized as a pivotal plane for the tool to easily perform a helical lifting application upon the upper cover plate through engaged threads, and thereby the air-tight state of the chamber can be easily removed.
The upper cover plate for an air-tight chamber is introduced to integrate a chamber body for forming the air-tight chamber, in which the chamber body provides a top surface to air-tightly match with a bottom surface of the upper cover plate. The upper cover plate further includes a plurality of thread holes engageable respectively with a plurality of the tools. The present invention is characterized on that at least one of the thread holes is formed as a through thread hole connecting to the bottom surface, and that the respective tool for engaging with the through thread hole includes a portion for penetrating the through thread hole and going beyond the bottom surface.
In the present invention, at least one of the thread holes should be formed as the through thread hole for engaging with the tool of the present invention, and the rest of the thread holes can be made as the conventional blind thread holes as described above in the background section. In accordance with the present invention, all of the thread holes can be formed as the through thread holes.
In the present invention, the tool for engaging with the through thread hole includes a hand bar, a stem bar and a thread part. The hand bar is used to receive an external torque for driving the tool helically along the through thread hole. The stem bar has two ends for fixedly connecting with the hand bar and the thread part, respectively. The thread part includes exterior threads for engaging with respective interior threads of the through thread hole. By providing the present invention, while the tool is applied to the through thread hole, the torque can be applied to the hand bar for rotating the thread part feeding along the through thread hole. As long as the thread part of the tool goes beyond the through thread hole of the upper cover plate and touches with the top surface of the chamber body, the top surface can be deemed as a pivot plane for the tool to rotate about the stem bar. Thus, further rotation of the tool can generate a lifting force contributed by the sliding threads between the thread part and the through thread hole for easily elevating the upper cover plate off the chamber body. Therefore, the air-tight state of the chamber can be easily broken.
In one embodiment of the present invention, the hand bar of the tool is preferably perpendicular to the stem bar.
In one embodiment of the present invention, the thread part further includes an extended portion for playing as the portion to go beyond the bottom surface of the upper cover plate.
In one embodiment of the present invention, the extended portion of the tool can further include a friction sleeve for wrapping around the exterior of the extended portion, by which the top surface of the chamber can be prevented from being scratched upon the tool rotating thereon. Preferably, the friction sleeve can be made of a Teflon material.
All these objects are achieved by the upper plate and the tool described below.